Malus Law Calculator
Calculate light intensity transmission through polarizers using Malus Law
Polarized Light Intensity Calculator
Intensity of incident polarized light
Angle between light polarization and polarizer axis
Malus Law Results
Malus Law Formula: I = I₀ × cos²(θ)
Calculation: 0.000e+0 = 0.000e+0 × cos²(0°) = 0.000e+0 × 1.0000
Interpretation: Almost no light transmission
Angle Analysis
Example Calculations
Polarized Sunglasses Example
Initial sunlight intensity: 1000 W/m²
Polarizer angle: 45° (partially blocking)
Calculation:
I = 1000 × cos²(45°) = 1000 × (0.707)² = 1000 × 0.5 = 500 W/m²
Result: 50% light transmission, reducing glare effectively
Photography Filter Example
Camera flash intensity: 50 W/m²
Polarizer angle: 30° (slight reduction)
Calculation:
I = 50 × cos²(30°) = 50 × (0.866)² = 50 × 0.75 = 37.5 W/m²
Result: 75% transmission, gentle light reduction
Key Angles & Transmission
Polarization Concepts
Linear Polarization
Light waves oscillating in a single plane perpendicular to the direction of propagation
Polarizer Axis
Direction along which the polarizer allows light to pass through
Dichroic Materials
Materials that selectively absorb light based on polarization direction
Understanding Malus Law
What is Malus Law?
Malus Law describes how the intensity of polarized light changes when it passes through a polarizer. The transmitted intensity depends on the cosine squared of the angle between the incident light's polarization direction and the polarizer's transmission axis.
Physical Mechanism
- •Polarizers contain aligned molecules that absorb light
- •Light parallel to molecular alignment is absorbed
- •Light perpendicular to alignment passes through
- •Partial transmission occurs at intermediate angles
Mathematical Formula
I = I₀ × cos²(θ)
- I: Transmitted light intensity
- I₀: Initial (incident) light intensity
- θ: Angle between polarization and polarizer axis
- cos²(θ): Transmission coefficient
Note: This law applies to ideal polarizers with 100% efficiency. Real polarizers may have additional losses.
Practical Applications
- •Photography: Reducing reflections and glare
- •Sunglasses: Blocking polarized light from surfaces
- •LCD displays: Controlling light transmission
- •Optical instruments: Measuring light properties
- •Scientific research: Studying material properties
- •3D movies: Creating stereoscopic effects